To the Editor: In their Rational Clinical Examination review, Dr Straus and colleagues1 comment that preparation of the skin should be performed in circular motion starting from the point of proposed lumbar puncture in an outward spiral. I am not aware of any clinical trial that has addressed the validity of this teaching. When I was introduced to the spiral technique during medical school in the 1970s, I was told that the concept was to avoid spreading organisms from the unprepped to the prepped skin. Studies have evaluated the use of povidone-iodine paint allowed to dry, but they have not specified a spiral technique.2,3 In the absence of supporting evidence, I believe that the spiral approach to skin preparation should be abandoned.